Electric cars
EV vs petrol calculator
A like-for-like look at what it costs to move the same miles: your current petrol or diesel car, a full electric car, or a plug-in hybrid — energy costs only, on your own figures.
The calculator is free, needs no account, and keeps your figures in your own browser.
Compare the carsAlso shows the electricity price at which the two would cost the same.
Same miles, different energy
Your mileage is converted into litres of fuel using your car's real miles per gallon, and into kilowatt-hours using the electric car's efficiency plus charging losses. Each is then priced at what you actually pay, so the difference is a difference in money, not in units.
Where the answer turns
Two things move it most: the share of charging done at home rather than in public, and whether you are on a cheap overnight rate. Change either and the comparison updates immediately, including the break-even electricity price.
Energy only, deliberately
No purchase price, depreciation, tax, insurance or servicing is included, and nothing here is a recommendation about which car to buy. It answers the running-cost question and leaves the rest to you.
Common questions
- Is an electric car cheaper to run than petrol?
- On energy alone it usually is when most charging happens at home, and the gap widens on a cheap overnight rate. It can narrow or disappear if much of your charging is public rapid charging, which the comparison shows rather than assumes.
- How is the petrol or diesel cost worked out?
- From your annual mileage, your car's miles per gallon and the pump price per litre, converted using imperial gallons. Enter the figures from your own driving rather than a manufacturer's number for a fairer comparison.
- How does a plug-in hybrid compare?
- A plug-in hybrid is modelled as part electric and part fuel, with its own engine fuel price and battery size. The result depends heavily on how much of your driving is done on the battery.
- What is left out of the comparison?
- Purchase price, depreciation, vehicle tax, insurance, servicing and emissions. This is a running-energy comparison only, so it answers one part of the decision clearly instead of every part vaguely.
- At what electricity price would the saving disappear?
- The calculator shows the break-even price — the electricity rate at which the electric car would cost the same to power as your current one. That is often a more useful number than the saving itself.